Electrical cut-out



Oct. 28, 1930.

G. KLUPFEL fr AL v ELECTRICAL CUT-OUT Filed May 5, 1928 Inventors Geofge Klupfel, George FLmcks, WWW

L-J Then" A cborneg.

Patented Oct. 28, 1930 PATENT OFFIQE MWQIM GEORGE 'KLUPFEL AND GEORGE F. LINCKS, F PITTSFIELD, MASSACHUSETTS, AS- SIGNORSTO'GENERAL ELECTRZC COMPANY, A CORPORATION OF NEW YORK ELECTRICAL CUT-OUT Application filed May 5, 1928.

The present invention relates to means for protecting electric power circuits and the translating apparatus connected thereto against-abnormal flow of current and more especially to'cut-outs adapted to be operated manually as switches to disconnect a branch circuit and the translating apparatus from the main supply circuit.

The object of our invention is the provision do of an improved high duty cut-out which shall be adapted for operation as a switch without dangerof injury to itself or to persons or things.

The'high duty cut-outs of the D & W type 115 as shown in Patents 1,195,790, 1,203,316 and 1,2d8,090 are in general use in this country,

but owing to their lack of capacity towithstand the destructive arcing incident to operation thereof as switches, it is the usual praco tice to interc'alate separate switch mechanisms in series therewith, although they are relatively expensive and consume valuable space.

One embodiment-of our invention is shown in the accompanying drawing, as applied to a D 1V type of cut out', in which Fig. l is a fragmentary section showing the fuse car rier, contacts and supports thereof; Fig. 2 is an underside view of the insulating ring, fuse carrier and contacts; Fig. 3 is a perspective view of a fuse carrier contact, and Fig. 4 is a similar view of a line terminal contact.

As is well known, the D & WV type of cutout comprises a pot or casing for the arc suppressing liquid with a fuse carrying plug introduced therein through a central aperture in the cover thereof and rotatable into and out of engagement with the stationary con tacts. As shown in the drawing, only a fragthe insulating ring mounted on the underside thereof, and the fuse carrying plug 3 in its normal closed circuit position. The top part 4 of the plug is of metal with means for making bayonet connection with the walls of the central aperture in the pot top 1 and the part of the plug within the pot is of insulating material and comprises a cylindrical middle section 5 and a lower end 6 in the form ment of the pot cover is indicated at l with Serial No. 275,443.

of a cylinder with opposite side portions cut away or deeply grooved at 7.

To the lower end of the cylindrical middle section 0 of the plug, at the upper ends of the side grooves 7, are fixedly secured the fuse by bolts l lon a radial web of the insulating supporting ring 2 and comprises two guide plates 16 andl"- held-in spaced relation by the bolts 14 and acontact plate 18 freely positioned between the guide plates and loosely connected thereto by two pins 19 fixed inthe contact plate 18 andlguided at their ends in parallel slots 20 in the guide plates 16 and 17. A helical spring 21 is interposed radially between the contact plate 18 and the inner wall of the insulating ring2 and acts to press the former inwardly. The spring 21 is held in position by small projections 22- and 23 on the rear of the contact plate 18 and the inner wall of the ring 22 respectively.

The operative face 24 of each of the line terminalcontact plates 18 is a plane surface with *the leading side edgev 25 rounded as shown in Fig- 2. The upper-guide plate 16 has a tapped hole- 26 for threaded engagement with a lead wire 27 and a flexible connection of braided fine wires is attached to the contact plate 18 and to the lowerguide plate 17. There is thus provided agood-electrio path between the contact plate 18 and the lead wire 27, while the formeris left free to move or float upon its mount and make contact practically throughout its entire surface with the corresponding'surface 9 of the fuse contact 8 irrespective of any eccentricity of movement of the plug-and parts carried thereby.

In the D &'VV-typeof cut-out, the fuse plug3 is rotatably movable through an angle of ninety'degrees back and forth and when rotated left-handedly from the operative position, as shown in full lines in Fig. 2 to the dotted line position of that figure, the floating spring-pressed line contacts 18 freely tilt and maintain engagement with the fuse contacts 8 until the shoulders or corners 28 of the lower end 6 of the plug, between the edge walls of the grooves 7 and the cylindrical surface of the plug end, move past the center of the line contacts 18 and tilt them back quickly from the dotted line position to the full line position. These contact parts are so positioned that when they separate from each.

other any arcing between them will take place upon the beveled edgeslO and 25 and thereby prevent any roughening or pitting of the operative contactsurfaces 9 and 24:. After the fuse and line contacts have been thus separated, the cylindrical surface of the lower end 6 of the plug continues in engagement with the line contacts 18 until the plug is reversely rotated and the circuit closed with the contacts'coming together with a quick action as the corners 28 of the plug recede from the center of the tiltable line contacts. It is to be understood that the contacts are maintained submerged in the arc extinguishing liquid as usual. I I V Whenthe fuse plug 3 is withdrawn from the cut-out, for refusing or any other purpose, the line contacts 18 move inwardly under the action of their springs until arrested by the pins 19 coming against the inner endsof the slots 20 where they are held in parallelism until the plug is reintroduced, the tip end 29 of which is'made conical to facilitate its entrance between them.

While we have shown and described the best'embodiment of the, invention known to us, we do not'desire to be restricted thereto.

- What we claim as new and desire to secure by Letters Patent of the United States is:

1. A cut-out comprising a pair of spaced line terminal contacts, and a plug carrying a pair of fuse terminal contacts rotatablebetween the line terminal contacts, both pairs of contacts having plane engaging surfaces normally disposed tangential to the path of rotation of the plug contacts and one pair of con- V 'tacts being fioatably mounted and free to tilt; l

2. A cut out comprising a pair of spaced spring-pressed fioatably mounted and tiltable contacts, and a plug carrying a pair of fuse terminal contacts rotatable between said line grooved plug being adapted rotatably to engage said tiltable line terminal contacts.

. 4:- An electric contact comprising a support having a pair of parallel guide ways at each end thereof, a contact plate provided with a pair ofv guide pins at each end thereof and freely and tiltably mounted in said guide ways and a spring pressing said plate from said support, I V I 5. An electric contact comprising two spaced plates each provided with parallel slots, and a contact plate disposed between said spaced plates and provided at each end with apair of projections adapted freely to enter and be retained by said slots, and a spring pressing centrally against said plate.

plate and one of said spaced plates. 7

7 FA cut-out comprising a spring-pressed freely tiltable line contact provided with a plane engagement surface, a plug rotatably' mounted opposite the plane surface of said,

tiltable contact and provided with a contact adapted tolengage said tiltable contact, and

an insulating shoulder on said plug adjacent said contact adapted upon rotation of said plug to traverse the plane surface of said tiltable contact and effect a snap movement thereof into and out of engagement with said plug contact.

In witness whereof we have hereunto set our hands this first day of May, 1928.

GEORGE KLUPFEL.

GEORGE F. LINGKS. 7

terminal contacts, both pairs of contacts hav- 7 ingplane engaging surfaces normally disposed tangential to the path of rotation of the plug contacts and beveled contact edges.

. 3. A cut-out comprising a pair of radially spring-pressed freely tiltable line terminal contacts, and a plug with longitudinal grooves in the opposite sides thereof and having fuse terminal contacts with plane engaging surfaces tangentially mounted in said 'grooves,'said fuseterminalcontacts and said 

